Two state legislators plan to introduce a bill to permit same-sex marriage in Pennsylvania, saying the time to seize upon growing national momentum is now.

In another push for the movement, Montgomery County on Tuesday appealed a state court order to stop issuing same-sex marriage licenses.

Efforts to legalize same-sex unions have failed in the past. But Reps. Steve McCarter and Brian Sims (both D., Phila.) say they are emboldened by a series of court rulings and initiatives in favor of same-sex marriage.

"Every seven to nine days, something is moving the process forward," McCarter said. "Marriage equality is going to come. It's only a matter of when."

He and Sims say they will introduce the Pennsylvania Marriage Equality Act after a Thursday morning news conference at LOVE Park.

The odds of passage?

"In a state where it is still legal to fire someone for being gay, it will be challenging," said Ted Martin, executive director of Equality Pennsylvania. "However, the world is changing swiftly, and I wouldn't discount anything these days."

Gov. Corbett opposes same-sex marriage, as do many members of the Republican-controlled legislature. Pennsylvania law defines marriage as between one man and one woman. Despite the energy and attention generated by gay-marriage advocates, opposition persists.

"The redefinition of marriage that a couple of people in the legislature [seek], this idea is a train wreck," Montgomery County pastor Bill Devlin said Tuesday. "It's not about equality, it's about children having both a mother and a father. It's a sad day in the Commonwealth when ideologues will sacrifice children on the altar of political expediency. We hope and pray to God that common sense will prevail."

Devlin, of Lower Moreland, was found not guilty of disorderly conduct last month following his arrest after he tried to reach the office of Attorney General Kathleen Kane, intending to pray for her to change her mind and defend the state marriage law in court.

Kane's decision not to defend the 1996 ban was among a series of events that have raised the urgency of the debate over same-sex marriage.

On Monday, Gov. Christie's administration asked New Jersey's highest court to hear an appeal of a ruling that the state must allow gay marriage. Last week, Judge Mary Jacobson agreed with those who argued that by denying same-sex marriage, the state had blocked gay couples from receiving benefits allowed by the federal government.

When the U.S. Supreme Court struck down the federal Defense of Marriage Act in June, the government had to provide the same benefits to married gay couples as it does to married heterosexual couples.

Following that ruling, two dozen plaintiffs filed a federal lawsuit seeking to overturn Pennsylvania's ban on same-sex marriage. The same month, Montgomery County Register of Wills L. Bruce Hanes began issuing marriage licenses to gay couples until he was stopped by a September Commonwealth Court ruling.

In asking the state Supreme Court on Tuesday to reconsider that ruling, Montgomery County Solicitor Raymond McGarry suggested that the Pennsylvania Health Department, which had sued the county, should not be involved in the issue, and that the dispute might not have even belonged in Commonwealth Court, which hears appeals of only certain agency decisions.

Last week, a lesbian couple who wed in Massachusetts and moved to Pennsylvania asked a federal court to force their new state to recognize their marriage.

Sims, who last year became the first openly gay candidate to win a seat in the legislature, said that after the Supreme Court decision, "more of my colleagues than we ever expected were ready to have the same-sex marriage conversation."

He says he expected the bill to have bipartisan support and said the chances of its eventual passage were 100 percent.

"The question is, 'When?' " he said. "I don't believe marriage equality is completely off the table, even given this governor and this legislature. One of the things we see from Republicans is, they are professionals at catching the political winds."

Those winds are blowing in favor of same-sex marriage, he said, with national polls showing majorities in favor.

Thirteen states and the District of Columbia allow same-sex marriage, among them Delaware, Maryland, New York, Connecticut and all the states north of it.

McCarter said it was unfair that gay people should be denied the same treatment as heterosexuals, and unacceptable that the extent of someone's rights can change upon crossing a state line.

More, he said, the growing acceptance of same-sex marriage threatens to leave Pennsylvania isolated, losing out on millions of dollars in wedding-related spending. New York City officials said the first full year of same-sex marriage brought $16 million in direct revenue, among $259 million in economic impact for hotels, restaurants and caterers.

"At some point we're going to be surrounded by these other states," McCarter said, "and Pennsylvania is going to look very antiquated."